PHOTOCHEM® Offers Unique Method of Measuring Antioxidants

Antioxidants are an essential part of the body’s defence mechanism against damage to proteins, DNA, lipid components of cell by free radicals such as superoxide, hydroxyl and peroxide.

Free radical damage can lead to ageing, cancer, asthma, atherosclerosis, cardiac infarction, and arthritis. The new PHOTOCHEM® from Analytik-Jena is available in the UK from Lambda Advanced Technology and is the first system to be able to quantify both water soluble and lipid soluble
antioxidants in a single instrument.

PHOTOCHEM® uses the principle of photochemiluminescence, combining very fast photochemical radical generation with highly sensitive luminometric detection. Superoxide anion free radicals are produced in the instrument by optical excitation of a photosensitiser, added in standardized volumes to the sample to be measured. These are partially removed by reaction with the antioxidants present in the sample. The remaining radicals cause the detector material, luminol, to luminesce, with the light being measured in a separate cell by a photomultiplier tube. The anti-oxidative capacity of the sample is quantified by comparison with a calibration curve created using standards of TROLOX® or ascorbic acid for lipid- and water-soluble antioxidants respectively.

This technique has considerable benefits over the conventional ELISA measurement method, since it generates a free radical for the measurement process that is actually found in nature. ELISA methods generate "synthetic" free radicals, whose reaction with antioxidants can be significantly different from "real" free radicals.

PHOTOCHEM® is extremely easy to use and offers very high sensitivity. Sample measurement times are < 3 minutes. There is no complex or time-consuming sample preparation and only a few microlitres of sample are needed. Sampling, measurement and rinse cycles are performed
completely automatically.

PHOTOCHEM® has applications in the food industry, medicine, biology, cosmetics, chemistry, environmental medicine and the pharmaceutical industry.